Process for producing colored shaped articles
CA 1189256 A · Owner: Ito, Tetsuo · Inventors: Ito, Tetsuo; Kiyomatsu, Yasuhiro; Shimizu, Takao
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A unformly colored shaped article which is resistant to discoloration and fading can be produced by immersing a shaped article, particularly a contact lens consisting of a polymer of at least one monomer selected from the group consisting of acrylates and methacrylates in a dyeing solution prepared by dissolving a watersoluble dye in a solvent capable of swelling said polymer, to swell and color the shaped article and then, drying the swollen shaped article.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted June 25, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 25, 2002.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.